Excavator: Update open-source publishing plugins (#1468)

Author: svc-excavator-bot

build.gradle

@@ -9,7 +9,7 @@ buildscript {
         classpath 'com.gradle.publish:plugin-publish-plugin:2.0.0'
         classpath 'com.palantir.baseline:gradle-baseline-java:6.68.0'
         classpath 'com.palantir.gradle.consistentversions:gradle-consistent-versions:3.7.0'
-        classpath 'com.palantir.gradle.externalpublish:gradle-external-publish-plugin:1.26.0'
+        classpath 'com.palantir.gradle.externalpublish:gradle-external-publish-plugin:1.27.0'
         classpath 'com.palantir.gradle.failure-reports:gradle-failure-reports:1.17.0'
         classpath 'com.palantir.gradle.gitversion:gradle-git-version:4.2.0'
         classpath 'com.palantir.gradle.guide:gradle-guide:1.25.0'